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soil health

I’ve been an earthworm fan for decades. At my Oakland, California home I dump vegetable scraps into a big plastic bin with worms. Once or twice a year I collect incredibly rich worm compost, teaming with roly-poly bugs (isopods), worms — and billions of critters I can’t see. My garden plants love it, and it’s free.

In agricultural soils, worms (different kinds, but worms nevertheless) can contribute significantly to soil respiration with a direct and sharp increase in the amount of carbon dioxide (CO2) released, as the number and length of worm canals increases. It turns out this soil respiration is critical to plant health.

The adage "we are what we eat" supports food and nutrition education programs across the country. The same goes for the farm — production of an abundant diversity of healthy crops depends on healthy soil and crop management techniques.

Farmers aren't born knowing how to do this, they learn. They learn from each other, and through programs like USDA's new soil health initiative. This is why we're working hard to make sure the next Farm Bill is a strong one that supports innovative farmer education.

Farmers who protect their soil using organic or other sustainable methods often encounter hurdles that other farmers do not. Current policies provide disproportionately little support for such farming practices depite the clear benefits — for the soil, the environment, human health and economic growth.

This week the U.S. Senate will have a chance to partially correct this by supporting Food and Farm Bill amendments that link crop insurance to sound farming practices. We know that good stewardship builds diverse agroecosystems that are inherently less risky than conventional sytems. Less risk with greater protection of soil and other natural resources? That's where I want my tax dollars to go.

This month and next the Senate Agriculture Committee, chaired by Sen. Debbie Stabenow (D-Michigan), will hold three more hearings. Hearings in the House begin next month. PAN and our allies in the National Sustainable Agriculture Coalition (NSAC) will be closely following the debates.

We hear Congress plans to improve crop insurance programs in recognition of these hardships, as negotiations for the 2012 Food and Farm Bill move ahead. But to really reduce risks, they should go one step further: tie crop insurance payments with an obligation to create healthy soil.

But there's hope for restoring this great carbon sink. The science and practice of ecological farming now show that farmers can effectively put carbon back into the soil – and that this, in turn, can be a huge help in the battle against climate change.

While there are hundreds of species of earthworms, anyone who makes compost knows the redworm, or Eisenia fetida. They make what's considered perhaps the richest form of natural fertilizer — a true friend to farmers and gardeners alike.

What you might not know is that very low levels of pesticides can kill these "black gold" producers. If they don't kill outright, pesticides can cause other serious harm, like reducing worms' ability to reproduce. Exposure to the neonicitinoid pesticide imidacloprid — well-known for its toxicity to honeybees — can also cause serious harm to worms, damaging DNA and deforming sperm. Bad news.

Healthy crops come from healthy soil. Soil fertility depends on an incredible diversity and abundance of soil critters, from the microscopic to the flying and creepy crawly. Together these critters cycle nitrogen (N) and many other essential minerals and nutrients, making them available to plants. The complexity of what goes on in healthy soil is truly awe-inspiring.

A key group of organisms that provide the soil with one nutrient that's often in short supply are the N-fixing soil bacteria. And according to a recent study by UK scientists, it turns out these organisms do a better job when they're working on organic farms.